A method for measuring the contribution an individual makes to group work is described, and its use is supported through a study of 57 university students aged from 20 to 46 years working in 8 groups of 4 to 10 members each. The method recognizes that the most valid sources of information on the contribution of each individual to the group work are the group members. The study relied on peer evaluation of the percentage contribution that each member made to the group work. Group members were also asked for a rationale for each evaluation given. The reliability of the individual's mark was indicated by the variance of the marks the group member received from his or her peers. Additional validity was provided by the qualitative agreement of the rationales. The group work was assessed separately using usual appropriate criteria. An individual's mark was calculated as his or her mean percentage of the group's mark, weighted by the number of people in the group. By separating the measurement of process from the assessment criteria for the group work, the method highlighted the cooperative intragroup dynamics. The method also allowed the identification of consistent patterns of correlations within group scores that indicate a problem common to students with low achievement in group work that is independent of the subject assessed.....read more